scholarly journals Insulin does not regulate vascular smooth muscle Na+, K+-ATPase activity in rabbit aorta

Diabetologia ◽  
1993 ◽  
Vol 36 (3) ◽  
pp. 212-217 ◽  
Author(s):  
D. A. Simmons ◽  
A. I. Winegrad
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Atpase Activity ◽  
Rabbit Aorta

Clofibrate and vascular smooth muscle: Actions on rabbit aorta preparations

1981 ◽  
Vol 72 (4) ◽  
pp. 323-329 ◽  
Author(s):  
Alan S. Fairhurst ◽  
Gerald Kent ◽  
Ralph E. Purdy
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Rabbit Aorta ◽  
Muscle Actions

Serum transcriptionally regulates Na(+)-K(+)-ATPase gene expression in vascular smooth muscle cells

1997 ◽  
Vol 273 (3) ◽  
pp. C1088-C1099 ◽  
Author(s):  
J. Nemoto ◽  
S. Muto ◽  
A. Ohtaka ◽  
K. Kawakami ◽  
Y. Asano
Keyword(s):  
Gene Expression ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Atpase Activity ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Fold Increase ◽  
Mrna Levels ◽  
Subunit Protein ◽  
Mrna Induction

The present study was designed to examine the effects of serum on Na(+)-K(+)-ATPase alpha 1- and beta 1-subunit gene expression in cultured vascular smooth muscle cells (VSMC) from rat thoracic aortas. Addition of 10% serum to VSMC for 24 h increased Na(+)-K(+)-ATPase activity 1.5-fold and alpha 1- and beta 1-subunit protein levels 1.9-fold. Serum (10%) caused a 3.5-fold increase in alpha 1-mRNA levels and a 6.7-fold increase in beta 1-mRNA levels, with peak elevations at 12 h. The protein synthesis inhibitor cycloheximide abolished serum-mediated beta 1-mRNA induction but did not affect serum-mediated alpha 1-mRNA induction. Protein kinase C (PKC) inhibitors (staurosporine A or calphostin C) or tyrosine kinase (TK) inhibitors (genistein or herbimycin A) significantly reduced serum-mediated beta 1-mRNA induction but had no effect on serum-mediated alpha 1-mRNA induction. Transfection experiments with the 5'-flanking sequences of the alpha 1- or beta 1-subunit genes linked to the luciferase reporter gene revealed that 10% serum caused 2.8- and 6.5-fold increases in luciferase activity, respectively. Among growth factors, only basic fibroblast growth factor (FGF) enhanced luciferase activities for the alpha 1- and beta 1-subunit genes. We conclude that 1) serum stimulates alpha 1- and beta 1-mRNA expression, alpha 1- and beta 1-subunit protein accumulation, and Na(+)-K(+)-ATPase activity; 2) serum-mediated beta 1-mRNA induction partly requires de novo synthesis of intermediate regulatory proteins and activation of PKC and TK, whereas serum-mediated alpha 1-mRNA induction occurs through PKC- and TK-independent mechanisms; 3) the 5'-flanking regions of the alpha 1- and beta 1-subunit genes are serum responsive; and 4) FGF mimics stimulatory effects of serum on promoter activities for the alpha 1- and beta 1-subunit genes.

Hyperglycemia increases endothelial superoxide that impairs smooth muscle cell Na+-K+-ATPase activity

2002 ◽  
Vol 282 (3) ◽  
pp. C560-C566 ◽  
Author(s):  
Sandeep Gupta ◽  
Eugene Chough ◽  
Jennifer Daley ◽  
Peter Oates ◽  
Keith Tornheim ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Superoxide Dismutase ◽  
Smooth Muscle ◽  
Steady State ◽  
Atpase Activity ◽  
Rabbit Aorta ◽  
Enhanced Chemiluminescence ◽  
Arterial Tissue ◽  
Reciprocal Change

Nitric oxide (NO) plays an important role in the control of numerous vascular functions including basal Na+-K+-ATPase activity in arterial tissue. Hyperglycemia inhibits Na+-K+-ATPase activity in rabbit aorta, in part, through diminished bioactivity of NO. The precise mechanism(s) for such observations, however, are not yet clear. The purpose of this study was to examine the role of superoxide in modulating NO-mediated control of Na+-K+-ATPase in response to hyperglycemia. Rabbit aorta incubated with hyperglycemic glucose concentrations (44 mM) demonstrated a 50% reduction in Na+-K+-ATPase activity that was abrogated by superoxide dismutase. Hyperglycemia also produced a 50% increase in steady-state vascular superoxide measured by lucigenin-enhanced chemiluminescence that was closely associated with reduced Na+-K+-ATPase activity. Specifically, the hyperglycemia-induced increase in vascular superoxide was endothelium dependent, inhibited by l-arginine, and stimulated by N ω-nitro-l-arginine. Aldose reductase inhibition with zopolrestat also inhibited the hyperglycemia-induced increase in vascular superoxide. In each manipulation of vascular superoxide, a reciprocal change in Na+-K+-ATPase activity was observed. Finally, a commercially available preparation of Na+-K+-ATPase was inhibited by pyrogallol, a superoxide generator. These data suggest that hyperglycemia induces an increase in endothelial superoxide that inhibits the stimulatory effect of NO on vascular Na+-K+-ATPase activity.

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